Figure 3.

Effect of PTX and endocytosis inhibitors on the sequestration/internalization of radiolabeled ligands in Y₁-transfected HEK293 cells. Cells were treated with filipin (1 μg ml⁻¹), MβCD (1 mM), hyperosmolar sucrose (0.4 M) or PAO (20 μM) for 30 min at 37°C or with PTX (200 ng ml⁻¹) overnight at 37°C. Cells were then incubated with either 50 pM [¹²⁵I] [Leu³¹, Pro³⁴]PYY (a) or [¹²⁵I] GR231118 (b) for 40 min. Radioactivity was counted after washing the cells with a hypertonic acid solution. Data are mean±s.e.m. of four to nine replicates and were analyzed by Student's impaired t-test, ^*P<0.01, ^**P<0.001.